The invention relates to a power booster sealing mechanism. More particularly, the present invention relates to a power booster with a sealing mechanism for surrounding a component that extends through the power booster and penetrates an internal wall.
Power boosters operating on a pressure differential, such as exists between the engine intake manifold of a vehicle and the atmosphere, are well known devices. In the case of a single stage power booster, a shell-like housing typically encloses at least one variable pressure chamber that is separated from a vacuum chamber by a diaphragm and its supporting wall. The diaphragm and supporting wall are axially moveable relative to the housing under variable pressure conditions. In order to achieve an increased boost effect, tandem power boosters have the interior of the housing subdivided by a housing divider wall separating a secondary variable pressure and vacuum chamber combination from the primary chamber pair. In all cases, a power piston is urged to move axially by the diaphragm(s) and actuates an output rod for operating the vehicle brakes through an engaged hydraulic master cylinder.
It has long been known that the weight of a power booster can be reduced by using thin-wall or lightweight material for the housing walls. When this is done, some additional structural support is obviously needed to maintain the structural integrity of the housing. One manner of providing the additional structural support is to extend a shaft or shafts through the housing to carry the generated loads, freeing the housing shell from this function. When axial forces are generated in the power booster, the shaft(s) hold the relative positions of the front and rear housing walls.
One significant problem that arises, when extending a shaft through the erstwhile hermetic chambers of a power booster, resides in a need to provide a secure seal assembly where the shaft passes through the structure.
The present invention is a power booster comprising a housing, a tube, and a seal. The housing includes a front housing section, a rear housing section, and a divider. The tube is mechanically fastened proximate the rear housing section and generally stationary relative to the rear housing section, with the seal between the divider and the tube.
The features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiment, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.